But before the Knicks could complete their choke against the Pistons, Al Harrington saved them. In making up for Friday’s brain freeze in Atlanta, Harrington nailed the game-clinching bucket, a right-wing 3-pointer he fired with no hesitation. The trey with 1:21 left lifted the lead from 6 to 9 points to put the Pistons away for good in a 104-92 matinee victory.

The Knicks, in snapping a three-game slide, moved to 9-11 and play their next five games on the road, starting Tuesday in Chicago.

“We play so fast, and try to keep the tempo up so fast, no lead is safe,” said Chris Duhon, who played the full 48 minutes, scoring a team-high 25 points with 9 assists.

Harrington celebrated with style after hitting the big shot, leaping in the air, swinging his arm and chest-bumping David Lee. Lee, who had 19 rebounds, set Harrington up with a great whip pass from under the basket.

In Atlanta Friday, Harrington passed up an open 3-pointer in the final seconds when the Knicks needed a trey to tie, dribbling instead to the hole.

“I was surprised Al passed up any 3-pointer at any point of a game,” coach Mike D’Antoni said jokingly. “That kind of shocked me in Atlanta.”

The last-second Atlanta fiasco raised the issue of who will take the big shot now that Jamal Crawford is gone. It probably will turn out to be Harrington.

“You’re only as good as your last shot, but that one was over with,” said Harrington, who finished with 18 points. “I was on to new horizons. I just had to move on.”

That the Knicks needed Harrington’s bomb in the last minute was shocking after they completely throttled the Pistons during a 65-43 first half.

The Pistons barely were awake for the noon tip-off, playing as if they had attended the same Saturday nightspot as the Warriors the weekend before. The dead Warriors gave up 138 points last Sunday. The Pistons did a good impersonation, rarely bothering to raise their hands on defense in the first half. The Pistons are 0-5 in Sunday games, 11-2 in non-Sunday games.

After four minutes, the Knicks were up, 10-0. The Pistons didn’t score until 7:40 left in the first quarter and were outscored 29-12 in the opening session.

“Detroit didn’t play their best in the first half,” Lee said. “Sometimes that happens in (Sunday) afternoon games.”

Allen Iverson, who finished with 18 points (6 of 18), was ticked afterward, not to mention in the opening minutes. On an early possession, Iverson drove the lane and got slapped, with no call. “[Damn] Dick,” he yelled at referee Dick Bavetta.

But this was not the referees.

“It is tough because regardless how well you play, the one thing you can always do every night is play hard,” said Iverson, whose team is just 7-8 since he donned a Pistons’ uniform. “There is no excuse for that. We get a lot of money to come out and perform.”

The Knicks committed 16 turnovers in the second half, their minds probably on the late-afternoon NFL game they planned to watch. The Pistons closed within five points 4:16 left. Detroit had three shots attempts that could have cut the lead to either 2 or 3 points.

Duhon was coming off two miserable games in which he posted 13 turnovers, admitting fatigue from all the minutes was setting in. But D’Antoni played Duhon the entire 48 minutes because the Knicks were struggling to hold on to their gigantic lead.

“It was a little bit of a gamble to go with him the whole time, but it kind of worked out,” D’Antoni said.